SAGE III Science and Validation Objectives for …...Mission Status •Launched Dec 10, 2001...
Transcript of SAGE III Science and Validation Objectives for …...Mission Status •Launched Dec 10, 2001...
C. Trepte, L. Poole, M. Pitts, L. Thomason, J. ZawodnyB. Pierce and L. Harvey
(NASA Langley Research Center)
SAGE III Science and Validation Objectives for SOLVE II
SAGE III Instrument
scan mirror
solar attenuator
secondary mirror
primary mirror
diffraction grating
CCD
folding mirror
Launched 10 December 2001 on Russian Meteor-3m spacecraft
Based upon a UV/Visible spectrometer used to obtain profiles of O3, aerosol, H2O, NO2, NO3, OClO, and temperature with a vertical resolution of ~1 km.
New configuration includes:CCD linear array for measurements between 290
and 1020 nmPhotodiode for aerosol measurements at 1550 nmFused-silicate attenuator plate enables lunar,
solar, and limb-scattering observations
Heritage:Stratospheric Aerosol Measurement (SAM);
Apollo-Soyuz (1975)SAM II; Nimbus 7 (1978-1993)SAGE I; AEM-B (1979-1981)SAGE II; ERBS (1984-present)
SAGE III Instrument Schematic
Science Data Products
Product Esitmated Precision
Altitude Range (km)
Aerosol Extinction (@385, 448, 521, 676, 756, 869,
1020, 1540 nm)5% 0-40
Aerosol Optical Depth (@ 521nm and longer)
5% N/A
Ozone Number Density 5% (Solar) 10%(Lunar)
6-85 16-35(Lunar)
NO2 Number Density 15% (Solar) 15%(Lunar)
10-50 19-37
H2O Number Density 15% 0-50OClO Number Density 25% (Lunar) 15-25NO3 Number Density 10% (Lunar) 10-55
Temperature and Pressure 2K 2%
0-85
Cloud Presence N/A 6-30
Mission Status
• Launched Dec 10, 2001• First solar data (Feb 28)
Sunset measurements ~ 100% Sunrise measurements ~ 97%Aerosol, O3, and NO2 data to be archived ~ Dec 15
• First lunar data on (Mar 5) Approximately 80% Moonset data acquiredLimited Moonrise data acquired. Revising flight software to improve tracking
• Primary 1.7 GHz spacecraft transmitter failed (Jan 1)• Spacecraft GPS/GLOSNAS failed• Etalon problem with Solar Attenuator• First limb-scattering data (Sep 8)
Validation/Science Objectives• Acquire correlative measurements
• determine relative biases between sensors• investigate impact of inhomogeneities
• Verify altitude registration• impact of clouds• variation of lunar albedo & disk illumination• new technique based on O2 O2
• Examine impact of attenuator correction procedure
• Examine T dependence of O3 cross-section in O2 A-band
• Support winter O3 loss studies (e.g, match campaign)
• PSC investigations
SAGE III Measurement Sequence
Effective Center of
Brightness
∆ h
MeasurementPackets
Terminator
Measurement Coverage
Attenuator Plate Correction
Attenuator Plate Correction
Ozone SAGE III vs. SAGE II
SAGE III (V1.06):9-May-02 – 10-May-02Lat: 50.04oN to 50.56oN21 Profiles
SAGE II:9-May-02Lat: 52.11oN to 52.84oN5 Profiles
NO2 SAGE III vs. SAGE II
SAGE III (V1.06):9-May-02Lat: 50.04oN to 50.56oN21 Profiles
SAGE II:9-May-02Lat: 52.11oN to 52.84oN5 Profiles
Quicklook Productse.g., aerosol extinction 1020 nm
QL data available ~ 6 pm day of observation in Sweden
Complete Level 1 & 2 data set will be transfered
Measurement Strategy
• Correlative measurements - along LOS (curtain observations)- perpendicular to LOS (slant path optical depth obs)- profile descent at satellite tangent location (in situ obs)
• Comparisons with SAGE III spectral survey
- SAGE event between 0 º - 40º W from Jan 30 - Feb 4
• Best moonset observation opportunity- Jan 25 or 26 over southern Scandinavia- local midnight
‘Strawman’ Flight Strategy
Satellite LOS
LaRC Forecast Support
LaRC Forecast Support
Forecast trajectories along SAGE, POAM LOS
Reverse Domain Filling techniques
T, wind, PV, Mixing Efficiency, etc.
URL catalogue
DAO driven (48 - 84 hr)
350, 450, 550, and 700 K
available by 6 am in Kiruna